The present invention pertains to the repair of metal structures which require thermal expansion in the repair operation.
In the railroad industry it is not uncommon to have rails fracture because of various reasons including fatigue, temperature extreme, loads borne, faulty ties. The repair of a fractured rail is accomplished by the welding together of the separated, spaced apart ends. Current practice in the repair of fractured rails includes the application of heat to rail segments adjacent the fracture to expand same to reduce the gap therebetween and permitting re-attachment of the ends by welding. Such fractures or separations are termed xe2x80x9cpull-apartsxe2x80x9d.
Current practice in the repair of broken or separated rails entails the saturation of a length of rope with diesel oil and placement of the saturated rope along a rail segment. Ignition of diesel oil soaked rope, often by a hand held flare, serves to heat the rail segment expanding same. Such a practice is time consuming, messy and, more importantly, puts repair personnel at risk of serious burns from accidental ignition of oil soaked clothing. Environmental restrictions may also be violated by such a practice as the use of diesel oil as a heat source results in airborne pollutants and residue, several feet in length, remaining along the rail bed. As burning takes place necessarily for several minutes considerable amount of airborne pollutants are released in each repair operation. Also of environmental concern is the diesel fuel poured on a rail to be heated and then welded. The oil, when burned, heats the rail with the unburned oil soaking into the rail bed and ground.
The present invention is embodied in a self-contained length of flammable material for placement on a damaged rail for heating of same in a repair operation.
The flammable core of the heat source is confined within a receptacle which permits convenient shipping, handling and installation on the rail. The composition includes an alcohol base with an additive to achieve a desired burn time and temperature for rail expansion. Ignition may be by a fuse applied to the pliable receptacle of the heat source. Sheath material is of minimal wall thickness to confine the flammable core in a secure manner while leaving minimal residue. The present article is placed lengthwise along a fractured rail segment and ignited applying heat to the segment for several minutes resulting in expansion of the segment to relocate the fractured ends toward one another to enable joining by welding. A fuse is preferably is applied to the sheath exterior to promote ignition. Ignition can be accomplished otherwise as by a fusee.
Important objectives include the provision of a heat source capable of heating several feet of a rail for expansion of same during repair of a rail pull-apart while minimizing pollution problems and reducing risk of burns to personnel encountered in the use of previous rail heating methods; the provision of a heat source capable of heating twenty or so feet of a railroad rail to the extent the rail expands lengthwise to position fractured rail ends proximate one another to enable rejoining of the rail ends by welding; the provision of a heat source which may be packaged, shipped and installed on a rail in a safe manner as flammable contents are confined with a non-injurious sheath; the provision of a heat source for heating metal structures such as a railroad rail and which utilizes synthetic fibers in combination with alcohol and fuel oil to provide the BTU output required for rail expansion.